Wheel

ABSTRACT

A wheel, particularly a light metal wheel, for motor vehicles, essentially consists of a spoke wheel center ( 20 ) and a wheel rim ( 10 ). In order to reduce weight and to increase the bending strength, which is of great significance in regard to contacts with curbstones and driving through potholes, profile segments ( 31 ) in the form of half-shell units, which form a continuous hollow chamber ( 41 ) in the direction of circumference, at least in sections, are provided in the area of an external base of the rim ( 14 ).

[0001] This Application is a Continuation, and claims the priority ofthe filing date, of 10/070,578, filed on Jul. 24, 2002 presentlypending.

[0002] The invention relates to a wheel, particularly a light metalwheel for motor vehicles, wherein each such wheel comprises a spokewheel center and a wheel rim, in which the wheel rim has an inner beadseat making a transition to an internal horn of the rim, and an outerbead seat making a transition into an external horn of the rim.

[0003] Such types of wheels enjoy very great popularity, particularly ina construction as light metal wheels, since, in addition to an increasedoverall aesthetic appearance of the motor vehicle, additional technicaladvantages can be attained.

[0004] In entirely general terms, the present trend is towards reducingthe weight of the wheel as much as possible. This is an additionalreason for the increasing spread of light metal wheels. The savings inweight relative to conventional steel wheels that is achieved isfrequently not very high, however, since the light metal alloys that areused mostly do not have the strength of steel. Such wheels musttherefore be designed with greater wall thicknesses, as the result ofwhich the weight advantage is partially lost again.

[0005] The task which forms the basis for the present invention istherefore that of further developing a wheel, particularly a light metalwheel for motor vehicles, in such a manner that it no longer has thedisadvantages stated. In particular, a wheel should be created whichpermits an additional reduction of weight or an improvement of themechanical characteristics relative to conventional wheels. direction ofthe circumference, which profile segments, at least in sections, areprovided in the area of the internal bead seat and the external beadseat.

[0006] Advantageous forms of implementation of the invention are statedherein.

[0007] The invention is based on the idea of forming hollow chambers inareas of the wheel that are subject to particularly heavy stresses,thus, in the area of the internal horn of the rim and the external hornof the rim.

[0008] These hollow chambers are comparable with closed hollow chamberprofile sections, which are known entirely generally from the area oflight construction and which permit a considerable increase in thestrength. In concrete terms, it is provided to apply profile segments,which each form hollow chambers in the direction of circumference, inthe area of the internal base of the rim and/or of the external base ofthe rim. As a general rule, the hollow chamber is developed continuouslyin the direction of circumference, so that an increase in rigidity,distributed optimally uniformly over the circumference, is provided. Inthe area of the internal horn of the rim, the increase in the bendingstrength is used to improve the so-called impact behavior. In the areaof the external horn of the rim, the aspect of the weight reduction ismost prominent.

[0009] One particularly weight-saving construction results if the hollowchamber assigned to the external base of the rim is combined with hollowchamber spokes. In this manner, a hollow chamber structure, which makespossible excellent rigidity values with simultaneously minimum weight,can be provided.

[0010] The construction of the hollow chambers is carried out by meansof profile segments which are attached to the wheel rim in the area ofthe internal base of the rim or of the external base of the rim and areconnected into a closed hollow profile.

[0011] One particularly simple construction results if the profilesegments are developed as shell units, particularly as half-shell units.These can be pre-manufactured in a simple way and manner and, as a rule,applied to the external circumference of the wheel rim. The individualsegments can be connected with one another by means of connectiontechniques which are known per se and have already proven their value,such as welding, adhesion, or flanging, for example. The connection islikewise carried out towards the wheel rim, so that a closed hollowchamber profile can be produced.

[0012] The geometrical configuration of the profile segments can beselected in such a manner that optimal results can be achieved inrelation to the bending strength that is being striven for. As a rule,however, at least one section of the specific profile segments of thebase of the rim—that is to say, the internal base of the rim or theexternal base of the rim—is configured so that the geometry isaccordingly provided in those areas as a seat or supporting surface forthe tires.

[0013] In accordance with one preferred variant, the profile segmentsare developed in a congruent manner in the area of the internal base ofthe rim and the profile segments in the area of the external base of therim. They can consequently be stored in inventory as so-called identicalparts, and permit optional application in the internal- or in theexternal area.

[0014] Finally, it is also possible to form the profile segments, bymeans of a non-cutting shaping process, from an annular bar integrallyformed on the wheel rim, particularly one cast integrally in a singlepiece. So-called ductile materials, which can be transformed under coldconditions, or cast alloys, which can be transformed under warmconditions, are suited for this.

[0015] The invention will now be depicted in further detail by means ofthe diagrams. These depict the following:

[0016]FIG. 1: Wheel in a half-section, first variant;

[0017]FIG. 2: Wheel in a half-section, second variant;

[0018]FIG. 3: Wheel in a half-section, third variant;

[0019]FIG. 4: Wheel in a half-section, fourth variant;

[0020]FIG. 5: Wheel in a half-section, fifth variant;

[0021]FIG. 6: Wheel in a half-section, sixth variant;

[0022]FIG. 7: Wheel in a half-section, seventh variant;

[0023]FIG. 8: Wheel in a view from the front.

[0024]FIG. 9: A side elevation of a wheel according to preferredembodiments of the invention, showing how two profile segment halfshells may be joined.

[0025] The essential construction of the wheel (1) is in agreement forall variants of design. It is also constructed, in the manner known perse, from a wheel rim (10) and a spoke wheel center (20).

[0026] The wheel rim (10) has an internal base of the rim or bead seat(16) and an external base of the rim or bead seat (14). These each makea transition axially outwardly into an internal horn or flange of therim (18) and an external horn or flange of the rim (12). A tire, notdepicted here, which is seated on the internal base of the rim (16) andthe external base of the rim (14), and is laterally applied on theinternal horn of the rim (18) and the external horn of the rim (12), isheld between the internal horn of the rim (18) and the external horn ofthe rim (12).

[0027] The wheel rim (10) makes a transition into a spoke wheel center(20), which has a multiplicity of spokes (22). The spokes (22) are, forreasons of weight savings, constructed as hollow spokes and each have aspoke hollow cavity (24). All variants of construction are accordinglyin agreement.

[0028] The variants of construction depicted in FIG. 1 to FIG. 3 haveprofile segments (31, 32, 33) which are attached in differentconfigurations in the area of the external base of the rim (14). Theyeach have the shape of half-shells, so that two profile segments (31,32, 33) are each applied, from the outside, onto the wheel (1) in thearea of the external base of the rim (14), and are connected solidlyboth with one another as well as well as with the wheel (1). In thisway, a hollow cavity (41, 42, 43), which is configured continuously inthe direction of circumference, is formed in the radial direction on theinside. A communicating connection with the spoke hollow cavities (24),through which an extremely stable and, at the same time, a rigid hollowchamber construction, is brought about, is present in the area of thespokes (22). This guarantees an impact behavior which is considerablyimproved in relation to the previously known contractions, which [impactbehavior] is particularly important in regard to unintended curbstonecontacts and driving over potholes. At the same time, this constructionis very light, as the result of which the total weight of the wheel (1)is reduced considerably.

[0029] In the variant in accordance with FIG. 1, the profile segment(31) is configured in an essentially “L”-shape and is axially supported,on one end, on the external horn of the rim (12) and radially, on theother end, in the area of the spokes (22) proceeding outwardly.

[0030]FIG. 9 is a side elevation of a wheel (1) showing how profilesegment half shells (31, 32, 33) may be joined at 100, by means of anyknown method of joining, such as welding, adhesion or flanging.

[0031] In the variant of construction in accordance with FIG. 2, theprofile segment (32) is beveled along a larger cross-sectional sectionon the external horn of the rim (12), over its complete surface. In thisway, an optimal supporting of that area of the profile segment (32)which serves as tire seat is guaranteed.

[0032] The variant in accordance with FIG. 3 is primarily distinguishedfrom that in accordance with FIG. 2 through the fact that the profilesegment (33) is guided out beyond the middle axis of the wheel (1). Inthis way, a sharp increase in the bending strength is achieved.

[0033] The variants of design in accordance with FIGS. 4 to FIG. 6 havea profile segment (31) which is in agreement with the variant of designin accordance with FIG. 1. In addition, profile segments (34, 35, 36),which each form additional hollow chambers (44, 45, 46), are provided inthe area of the internal base of the rim (16). The profile segments (34,35, 36) are, in turn, designed as half-shell units, which are solidlyconnected both with one another as well as with the wheel (1). Theythereby increase the bending strength in the area of the internal hornof the rim (18), as the result of which the impact behavior is alsodecisively improved in this area. This is particularly important here inrelation to driving over potholes.

[0034] In the variant of design in accordance with FIG. 4, the profilesegments (34) are applied to be positioned radially and externally onthe wheel (1) and form, together with the internal horn of the rim (18),the internal base of the rim (16). In the radial direction, the profilesegments (34) support the tires directly. (1) and form, together withthe internal horn of the rim (18), the internal base of the rim (16). Inthe radial direction, the profile segments (34) support the tiresdirectly.

[0035] In the variant of design in accordance with FIG. 5, the profilesegment (35) is provided positioned radially internally, and therebyserves exclusively for increasing the rigidity. The tire seat isadditionally formed directly on the wheel rim (10).

[0036]FIG. 6 depicts a variant in which the profile segment (36) isdesigned to be congruent with the profile segment (31). This variantmakes possible an identical design of the parts, since the profilesegments (31, 36) can optionally be used in the area of the internalbase of the rim (16) or of the external base of the rim (14).

[0037]FIG. 7 depicts an additional variant, in which a profile segment(34) in agreement with that of FIG. 4 is used in the area of theinternal base of the rim (16). The characteristic feature lies only inthe fact that, during the shaping of the wheel (1), a molded blank (50)(depicted in dotted line) is used which has, in the area of the externalbase of the rim (14), an annular bar or radially extending flange (30)having a radially outwardly disposed free edge (51) which is, in a cold-or hot transformation process, formed into a profile segment (37) and isbrought to application on the external horn of the rim (12). In thismanner, the profile segment (37) is formed in an integral manner withthe wheel (1) without requiring additional construction components forthe realization of the invention. Although not depicted here, acorresponding procedure is also possible in the area of the internalbase of the rim (16). The embodiment of FIG. 7 also includes hollowchamber 47.

[0038] Although the concept in accordance with the invention isessentially also suitable for wheels of steel, it preferably findsapplication in light metal standard norm EN 573-3, namely EN AW-AIMg3 orEN AW-AISilMgMn, are suitable as materials for the profile segments.Both of the last-named materials involve so-called ductile materials,which can be transformed under cold conditions. Furthermore, it isobviously possible to manufacture the wheel and the profile segmentsfrom the same material.

Listing of References:

[0039]1 Wheel.

[0040]10 Wheel rim.

[0041]12 External horn of the rim.

[0042]14 External base of the rim.

[0043]16 Internal base of the rim.

[0044]18 Internal horn of the rim.

[0045]20 Spoke wheel center.

[0046]22 Spoke.

[0047]24 Spoke hollow cavity.

[0048]30 Annular bar or radially extending flange

[0049]31 Profile segment.

[0050]32 Profile segment.

[0051]33 Profile segment.

[0052]34 Profile segment.

[0053]35 Profile segment.

[0054]36 Profile segment.

[0055]37 Profile segment.

[0056]41 Hollow chamber.

[0057]42 Hollow chamber.

[0058]43 Hollow chamber.

[0059]44 Hollow chamber.

[0060]45 Hollow chamber.

[0061]46 Hollow chamber.

[0062]47 Hollow chamber.

[0063]50 Molded blank.

[0064]51 Radially outwardly disposed free edge.

1. A wheel, particularly a light metal wheel for motor vehicles,comprising: a spoke wheel center (20) and a wheel rim (10); wherein thewheel rim (10) further comprises an internal bead seat (16) and anexternal bead seat (14) which each make a transition into an internalflange (18) and an external flange (12); wherein at least one profilesegment (31, 32, 33, 34, 35, 36, 37), which continuously form at leastone hollow chamber (41, 42, 43, 44, 45, 46, 47) in the direction ofcircumference, at least in sections, is provided proximate the internalbead seat (16) and/or of the external bead seat (14); and wherein the atleast one profile segment (31, 32, 33, 34, 35, 36, 37) is initiallyconfigured as a substantially radially extending flange (30), emanatingfrom the wheel rim between the inner and outer flanges, and having aradially outwardly disposed free edge (51), which radially extendingflange (30) is reformed to curve back upon the wheel rim with the freeedge (51) rejoined to the wheel rim, to define a hollow spacetherebetween.